CN110038488A - A method of hydrogen is produced using organic solid castoff - Google Patents

Abstract

The invention belongs to the field of organic solid waste recycling, and provides a method for utilizing organic solid waste to produce hydrogen, which is characterized by comprising the following steps: combining an alkaline substance containing hydroxide with water in a ratio of 1:10 to 20:1 Mix the organic solid waste and the alkaline solvent system according to the mass ratio of 1:1000~2:1, and stir at minus 20~150℃ to obtain the organic solid waste solution or Suspension; adding a hydrogen-producing catalyst into the organic solid waste solution, and producing hydrogen under the conditions of illumination and stirring; after the reaction is completed, the unreacted remaining materials are recovered. The method provided by the invention does not require pretreatment of biomass and plastics, does not require additional energy input in the conversion process, can be converted at room temperature and under natural lighting conditions, has high hydrogen production efficiency, and does not cause secondary pollution.

Description

A kind of method that utilizes organic solid waste to produce hydrogen

technical field

The invention belongs to the field of organic solid waste treatment, and particularly relates to a method for producing hydrogen from organic solid waste.

Background technique

Solid waste refers to solid and semi-solid waste materials produced by human beings in production, consumption, life and other activities, among which organic solid waste mainly refers to discarded organic items and substances. In terms of sources, the main organic solid wastes include agricultural organic wastes (mainly including crop straws and vines, livestock and poultry manure and aquatic wastes, etc.), industrial organic wastes (mainly including high-concentration organic wastewater, organic waste residues, etc.), municipal organic wastes (mainly including landscaping waste, municipal sludge, slaughterhouse animal contents, kitchen waste, etc.) three categories.

Using organic solid waste as raw material to produce hydrogen is an effective way to control environmental pollution and develop clean energy, but the use of organic solid waste requires harsh reaction conditions and chemical conversion processes. For example, biomass can be decomposed into gaseous products containing hydrogen, carbon monoxide, carbon dioxide, and methane by gasification, which typically requires temperatures as high as 750 °C to decompose organic structures, along with the production of biochar and bio-oil. The pyrolysis process has low efficiency, high energy consumption and low selectivity, and the obtained gaseous products, biochar and bio-oil also require a series of complex separation and purification and upgrading conversion processes, which further reduces the conversion efficiency and economy.

Using biomass as a raw material for hydrogen production is also an effective way to realize biomass resource utilization. To improve the economics of converting organic solid waste to hydrogen, solar energy can be used instead of thermal energy input. Solar energy is a renewable energy source, and there have been numerous studies on photocatalytic hydrogen production using biomass-derived compounds as feedstocks. Recent studies have demonstrated that CdS/CdO _x quantum dots are used in KOH solution to directly catalyze the decomposition of unpretreated biomass and plastics for hydrogen production under the action of visible light, but the current hydrogen production efficiency is still very low ( ). Due to the low solubility of biomass in KOH solution, the mass transfer between the reaction substrate and the catalyst is limited, which greatly limits the hydrogen generation rate.

The design of new photocatalytic materials, and the regulation of their solubility, dispersion and photocatalytic properties by adjusting their composition and introducing co-catalysts are very necessary to achieve efficient photocatalytic conversion of biomass. At the same time, the development of an alkaline solvent system that can efficiently dissolve cellulose and hemicellulose at room temperature will help to improve the contact efficiency of biomass and photocatalysts, thereby further improving the efficiency of photocatalytic reactions. In addition, since lignin absorbs light, which is also an important factor limiting the efficiency of photocatalytic reaction, the preferential depolymerization of lignin to obtain high-purity cellulose and hemicellulose also helps to further improve the efficiency of biomass decomposition for hydrogen production.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of high cost, high energy consumption, low efficiency and low selectivity of traditional organic solid waste hydrogen production technology, and to provide a method for photocatalytic organic solid waste hydrogen production. The present invention provides a method for utilizing organic solid waste to produce hydrogen, which is characterized by comprising the following steps:

The alkaline substance containing hydroxide and water are mixed according to the mass ratio of 1:10~20:1 to obtain an alkaline solvent system;

The organic solid waste and the alkaline solvent system are mixed according to the mass ratio of 1:1000~6:10, and stirred under the condition of minus 20~150 ℃ to obtain the organic solid waste solution;

The hydrogen production catalyst is added to the organic solid waste solution, and the hydrogen production is carried out under the conditions of illumination and stirring;

After the reaction is completed, the unreacted residual material is recovered.

The method for producing hydrogen by utilizing organic solid waste, wherein the organic solid waste includes crop straw, forestry waste, kitchen waste, waste plastic, cellulose, hemicellulose, lignin, lignocellulose, monosaccharide, Amino acids, polysaccharides or organic acids.

The method for producing hydrogen from photocatalytic organic solid waste, wherein the alkaline solvent system comprises a hydroxide-containing quaternary ammonium alkali aqueous solution, a hydroxide-containing quaternary phosphate alkali aqueous solution, and an ionic liquid aqueous solution containing hydroxide anions, Or the aqueous solution of the mixture of the above alkaline substance and inorganic base including sodium hydroxide, potassium hydroxide or ammonium hydroxide. Quaternary ammonium bases include a class of compounds with the general formula R ₄ NOH, where R is four identical or different aliphatic or aromatic hydrocarbon groups; quaternary phosphate bases include a class of compounds with the general formula R ₄ POH, wherein R It is four same or different aliphatic or aromatic hydrocarbon groups; ionic liquids containing hydroxide anions include ionic liquids composed of hydroxide anions and imidazoles, pyridines and pyrroles cations.

In the method for hydrogen production using organic solid waste, the hydrogen production catalyst includes a photocatalytic material and a hydrogen production co-catalyst. Photocatalytic materials include single-molecule photocatalytic materials, inorganic layered compound photocatalytic materials, quantum dot photocatalytic materials, metal oxide semiconductor materials, metal nitrides, metal carbides, metal sulfide semiconductor materials, zeolite materials, nitride Carbon materials, perovskite materials, metal organic framework materials, organic supramolecular photocatalytic materials, and doped materials and composite materials composed of the above materials.

The method for producing hydrogen by utilizing organic solid waste, wherein the hydrogen production co-catalyst comprises: chloroplatinic acid, chloroauric acid, metal complexes, metal nanoparticles, metal single atoms, metal alloys, metal oxides, metal sulfides .

In the method for producing hydrogen from photocatalytic organic solid waste, the illumination conditions include sunlight and light energy generated by various artificial light sources.

Preferably, the organic solid waste described in the present invention includes crop straw, forestry waste, waste plastic or cellulose.

Preferably, the alkaline solvent system of the present invention comprises an aqueous solution of tetrabutylphosphorus hydroxide or an aqueous solution of tetrabutylammonium hydroxide.

Further preferably, the alkaline solvent system of the present invention comprises an aqueous solution of 30-65 wt% tetrabutylphosphorus hydroxide and an aqueous solution of 30-65 wt% tetrabutylammonium hydroxide.

Preferably, the hydrogen production catalyst of the present invention includes cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, and perovskite quantum dots.

Preferably, the lighting conditions described in the present invention include sunlight and simulated sunlight.

The advantages and beneficial effects of the present invention are as follows: the present invention provides a method for preparing hydrogen by utilizing organic solid waste, the method provided by the present invention does not require pretreatment of biomass and plastics, and the conversion process does not require additional energy input, The conversion can be carried out at room temperature and under natural lighting conditions, with high hydrogen production efficiency and no secondary pollution.

Detailed ways

The present invention is further described in detail through the following examples, but the technical contents described in the examples are illustrative rather than restrictive, and should not limit the protection scope of the present invention accordingly.

Example 1

Add 0.2 g of wood into a 50 mL reactor, add 10 mL of 40 wt% tetrabutylphosphorus hydroxide aqueous solution, and stir at room temperature for 1 hour. 0.1 g of CdS quantum dots were added, and the stirring speed was kept at 700 r/min, and the reaction was carried out under simulated sunlight irradiation. After 24 hours, the reaction produced 1.3 mmol of hydrogen.

Example 2

0.2 g of corn stover was added to a 50 mL reactor, 10 mL of 40 wt% tetrabutylammonium hydroxide aqueous solution was added, and the mixture was stirred at room temperature for 1 hour. 0.1 g of CdS quantum dots were added, and the stirring speed was kept at 700 rpm. The reaction was carried out under simulated sunlight irradiation, and 1.5 mmol of hydrogen was generated after 24 hours of reaction.

Claims (12)

1. the present invention provides a kind of method that utilizes organic solid waste to produce hydrogen, it is characterized in that comprising the following steps: mix the alkaline substance containing hydroxide and water according to the mass ratio of 1:10～20:1, obtain alkaline Solvent system; mix organic solid waste and alkaline solvent system according to the mass ratio of 1:1000~6:10, stir at minus 20~150 ℃ to obtain organic solid waste solution; add hydrogen production catalyst to organic solid In the waste solution, hydrogen production is carried out under the conditions of light and stirring. 2. The method for producing hydrogen from organic solid waste according to claim 1, wherein the organic solid waste comprises crop straw, forestry waste, kitchen waste, waste plastic, cellulose, hemicellulose, wood cellulose, lignocellulose, monosaccharides, amino acids, polysaccharides or organic acids. 3. The method for producing hydrogen by utilizing organic solid waste according to claim 1, wherein the alkaline solvent system comprises a hydroxide-containing quaternary ammonium alkali aqueous solution, a hydroxide-containing quaternary phosphorus alkali aqueous solution, a hydrogen-containing The ionic liquid aqueous solution of oxyanion, or the aqueous solution of the mixture of the above-mentioned basic substance and inorganic base including sodium hydroxide, potassium hydroxide or ammonium hydroxide. 4. The quaternary ammonium base includes a class of compounds with the general formula R ₄ NOH, where R is four identical or different aliphatic or aromatic hydrocarbon groups; the quaternary ammonium base includes a class of compounds with the general formula R ₄ POH, the formula where R is four identical or different aliphatic or aromatic hydrocarbon groups; ionic liquids containing hydroxide anions include ionic liquids composed of hydroxide anions and imidazole, pyridine and pyrrole cations. 5. The method for producing hydrogen from organic solid wastes according to claim 1, wherein the hydrogen producing catalyst comprises a photocatalytic material and a hydrogen producing co-catalyst. 6. Photocatalytic materials include single-molecule photocatalytic materials, inorganic layered compound photocatalytic materials, quantum dot photocatalytic materials, metal oxide semiconductor materials, metal nitrides, metal carbides, metal sulfide semiconductor materials, zeolite materials, Carbon nitride materials, perovskite materials, metal organic framework materials, organic supramolecular photocatalytic materials, and doped materials and composite materials composed of the above materials. 7. The method for producing hydrogen by utilizing organic solid wastes according to claim 1, wherein the hydrogen production co-catalyst comprises chloroplatinic acid, chloroauric acid, metal complexes, metal nanoparticles, metal single atoms, metal alloys , metal oxides, metal sulfides. 8 . The method for producing hydrogen from organic solid waste according to claim 1 , wherein the illumination conditions include sunlight and light energy generated by various artificial light sources. 9 . 9 . The method for producing hydrogen from organic solid waste according to claim 1 , wherein the organic solid waste comprises crop straw, forestry waste, waste plastic, hemicellulose or cellulose. 10 . 10. The method for producing hydrogen from organic solid wastes according to claim 1, wherein the alkaline solvent system comprises an aqueous solution of tetrabutylphosphorus hydroxide or an aqueous solution of tetrabutylammonium hydroxide. 11. The method for utilizing organic solid waste to produce hydrogen according to claim 1, wherein the alkaline solvent system comprises a concentration of 30-65 wt% tetrabutylphosphorus hydroxide aqueous solution and 30-65 wt% tetrabutylammonium hydroxide aqueous solution. 12. The method for hydrogen production using organic solid waste according to claim 1, wherein the hydrogen production catalyst comprises cadmium sulfide quantum dots, cadmium selenide quantum dots, cadmium telluride quantum dots, and perovskite quantum dots.